The prior art is replete with transistor-based electronic circuits designed to support high speed data communication applications. Traditionally, transistor-based circuits that employ a certain manufacturing technology have practical limitations on the power supply voltage. In this regard, the power supply voltage should not exceed the “breakdown” voltage (which is determined by the particular manufacturing technology) for the transistors. If the breakdown voltage is exceeded, then the reliability of the transistors can be adversely affected and performance of the circuit can suffer.
In some circuits, the power supply voltage is related to the quality of the output signal(s). For example, in a ring oscillator stage, a higher power supply voltage (VDD) results in a higher output voltage swing, which in turn corresponds to a lower amount of phase noise and improved performance. Unfortunately, circuit design restrictions do not always allow the use of an unlimited power supply voltage. Indeed, high speed circuits utilize transistors with small channel lengths; these transistors have a relatively low breakdown voltage compared to larger transistors.
Accordingly, there exists a need for circuits that can utilize higher power supplies than the transistor technology limit, while still satisfying the reliability requirements for the transistors in the circuits.